By the time of Shaddam IV, while they were still formidable, their strength had been sapped by overconfidence, and the sustaining mystique of their warrior religion had been deeply undermined by cynicism.

You’re deliberately attempting to undermine my faith in my abilities as a Mentat," he rasped.

There are no more uses of "undermine" in the book.

Show samples from other sources

Her father had a way of undermining his sister’s lectures on the innate superiority of any given Finch: he always told his daughter the rest of it, quietly and solemnly, but Jean Louise sometimes thought she detected an unmistakably profane glint in Atticus Finch’s eyes, or was it merely the light hitting his glasses?

Harper Lee -- Go Set a Watchman

He cocked his head, trying on his "I’m so wholesome" routine, but his bloodshot eyes undermined his efforts.